The overall aim of this proposal is to support the continuing development of the applicant as a research clinician and independent scientist in the field of drug abuse treatment. Three objectives drive the applicant's work: 1) develop pharmacotherapies that consider the heterogeneity of substance abusers 2) provide mentorship to junior clinical investigators, and 3) contribute service to the field. Although there is a growing literature of various pharmacologic agents for alcohol, opiate or cocaine dependence, there are a limited number of well-controlled trials that have targeted certain psychiatric comorbidities such as ADHD, depression or anxiety disorders. Further, there are scant empirical data regarding targeted pharmacologic interventions for marijuana dependence. During tie proposed K02 competing continuation, the applicant will direct two studies to develop pharmacologic treatment for marijuana dependence. One of the studies will target marijuana withdrawal (P50 09236) and the other study will focus on marijuana-dependent individuals with depression (DA 015451). Extending this approach to other comorbid disorders, the applicant will collaborate with junior investigators who are targeting alcohol dependent individuals with anxiety disorders and schizophrenia. Working with experienced investigators, the applicant plans to 1) better understand the antecedents to alcohol and drug abuse and 2) expand the applicants expertise in utilizing behavioral interventions. Finally, the applicant will continue to contribute to a variety of educational activities at the National and local level, provide ongoing mentorship to young clinical investigators, and offer service to the Substance Abuse field.